Magnetic Anisotropy of Amorphous Gd-R-Co (R=Tb, Dy, Ho, Er) Films

Abstract

Dependence of anisotropy constants K _u on rare earth atoms in rare earth-transition metal amorphous films was studied. To minimize the influence of the preparation condition on K _u, Gd-R-Co (R=Tb, Dy, Ho, Er) films in which the compositions of R are small were chosen and the magnetic torque was measured. It became clear that even in amorphous films, K _u is mainly determined by the single atomic character of an added rare earth element. This result suggests that the direction of 4f electron clouds may be aligned through a structural anisotropy such as pair-ordering or an anisotropic microstructure.